Aircraft typically have a fuselage and two or more wings that are cantilevered outward from the fuselage of the aircraft. In general, higher aspect ratio wings produce more efficient flight than lower aspect ratio wings. An aspect ratio of a wing is the ratio of its length to its breadth (chord). Therefore, longer, narrower wings are generally more efficient than shorter, wider wings. However, during flight aerodynamic forces are exerted on the wings by the surrounding air due to the relative motion between the wings and the air. Longer wings are therefore generally subject to more bending stresses than shorter wings, which cause the wings to deflect and/or twist more during flight. This deflection and/or twisting can cause undesired drag and/or lift. To address this problem, some aircraft utilize relatively shorter, more rigid wings that are less susceptible to the stresses caused by the aerodynamic forces, which reduces the amount of deflection and/or twisting of the wing. However, these shorter, stiffer wings are heavier because of their rigid structural design and are less efficient than higher aspect ratio wings.
Other known aircraft such as, for example, those with longer and/or lighter wings, employ fixed or static struts between the wings of the aircraft and the fuselage (or another wing) to support the wings during flight. However, even with static struts, the wings are still subject to deflection and/or twisting due to aerodynamic loads. Particularly, a section of the wings outboard of the struts tends to deflect and/or twist under aerodynamic loads, which causes undesired drag and/or lift.
Additionally, some known aircraft store fuel (e.g., gas) within the wings of the aircraft. During flight, the weight of the wings decreases as the fuel within the wings is used. As a result, the wings become lighter during flight and, thus, are more easily deflected or deformed by aerodynamic loads. Thus, the shape of the wing changes during flight and may produce undesired drag and/or lift.